The invention relates to a rotor for a vane cell pump—in particular, for a vacuum pump—with a base body that is made of plastic and can be driven by rotation, and that rotates about an axis of rotation during operation, wherein the base body comprises a guiding section for slidably receiving a pump vane and wherein the base body is flanked in the direction of the axis of rotation by a first bearing surface and a second bearing surface. The invention further relates to a vane cell pump—in particular, a vacuum pump—comprising such a rotor.
Rotors for vane cell pumps are widely known from the prior art. Such rotors typically comprise a circular cylindrical guiding section with at least one vane shaft for slidably accepting a pump vane, wherein, on both sides of the guiding section, circular cylindrical bearing surfaces are respectively provided that are accommodated in appropriately corresponding bearing recesses of a pump housing, so that the rotor is rotatably mounted in the pump housing. In the region of the guiding section, such rotors have a larger outer diameter than in the region of the bearing surfaces, so that between the guiding section and the bearing surfaces, a shaft shoulder is provided that can also be used as a stop in the bearing recesses of the pump housing. Such a rotor is known from DE 10 2012 210 048 A1, for example.
Rotors for vane cell pumps are often made of metal, wherein these rotors are cast with lost molds. Furthermore, it is, however, also known to produce rotors for vane cell pumps using the plastic injection molding process. For these rotors made of plastic, it has, however, been shown that a solid construction of the base bodies of the rotors can result in the formation of blowholes. In order to avoid the formation of blowholes, it is known from the prior art to provide recesses in the base body in the circular ring-shaped shaft shoulder of the guiding section, which has a larger diameter than the bearing surfaces. Such recesses can, however, only be realized in comparatively short rotors with a comparatively large diameter or a comparatively large shaft shoulder. In comparatively long rotors with a comparatively small diameter, this approach is, however, problematic, since the differences between the diameters of the guiding section and the bearing surfaces are not suitable for the formation of sufficiently large recesses.